Flame hardening apparatus



Dec. 28, 1948. E. A. FURKERT 2,457,654

FLAME HARDENElNG APPARATUS Filed July 24, 1943 4 Sheets-Sheet 1fry/672707? [7725 A fir/Fer? Dec. 28, 1948. E. A. FURKERT FLAMEHARDENING APPARATUS W W MN Dec. 28, 1948. I UR 2,457,654

FLAME HARDENING APPARATUS Filed July 24, 1943 4 Sheets-Sheet 3 M UWQ/WDec. 28, 1948. E. A. FURKERT FLAME HARDENING APPARATUS 4 Sheets-Sheet 4Filed July 24, 1943 rs J65 Patented Dec. 28, 1948 UNITED STATES PATENTOFFICE 8 Claims.

This invention relates to flame hardening apparatus.

In the hardening of cylindrical members, such as gears in particular, itis desirable that the heat be applied uniformly to the surface orsurfaces to be hardened especially where a flame heating method isemployed wherein the necessary heating is effected in a matter ofminutes as compared with methods where the articles are heat treated forperiods of several hours duration.

In the apparatus for flame hardening disclosed in my co-pendingapplication Serial No. 416,613, filed October 27, 1941, now Patent No.2,407,230, granted September 10, 1946, the gear to be hardened iselevated into a heating station which is located centrally of a batteryof rotary gas bumers which deliver the flames to selected portions ofthe stationary gear. It is desirable that the gear being hardened betruly centered with respect to the rotary burners so that the flame fromeach burner will provide a uniform heating effect annularly of the gearas the flames rotate. Where a gear is positioned slightly off centerwith respect to the rotary burners or where eccentric movements of theburners occur with respect to the gear, as from vibrations or othercauses, the heating effect of any flame will not be uniform throughoutits annular path of infringement upon the gear. Such apparently minorvariations in the application of heat may produce non-uniformity inhardness or produce warpage, especially where the total .time requiredfor heating a gear surface to a hardening temperature is of relativelyshort duration and hence it is desirable that such variations be avoidedwhere a high uniformity in hardness of a gear surface, withoutdistortion of the gear, is sought.

One object of the invention therefore is to provide means for elevatinga member to be hardened into a heating position with respect to abattery of rotary burners which assures that the member will be centeredaxially with respect to all the burners and will be maintained in thatrelation during the heating operation for insuring uniformity of heatingeffect in all portions of 'the annular path of impingement of the flameof a burner upon the member.

Another object of the invention is to provide an improved gear elevatingmechanism for automatically engaging a gear for elevating the same intoa position accurately centered with respect to rotary heat applyingmeans and cooperating mechanism for automatically releasing the gearupon deposition thereof in a quench tank.

An additional object of the invention is to pro- 2 vide flame hardeningapparatus whereby gears or similar articles can be heat treated inrelatively rapid succession by an attendant, including im- -tank tominimize cooling in the interim between heating and quenching.

More specific additional objectsof the invention relate to the provisionof automatic pick-up and release mechanism for handling gears or similararticles to be heated for facilitating the hardening operations.

An additional object of the invention is to provide a quench tankmovable to a position beneath the burners to receive a heated gear andto a position more remote from the burners for reducing unnecessaryheating of the quenching liquid by the burners.

Other objects of the invention relate to various features ofconstruction and arrangement of parts which will be apparent from aconsideration of the following specification and accompanying claimswherein:

Figure 1 is a broken side elevation of apparatus illustrative of thepresent invention;

Fig. 2 is a broken end elevation of the apparatus shown in Fig. 1 asviewed from the right thereof;

Fig. 3 is a sectional view taken approximately on the line 3-3 of Fig.1;

Fig. 4 is an enlarged vertical sectional view of a gear elevating anddepositing mechanism;

Fig. 5 is an enlarged broken elevation of the automatic gear carrierforming a part of the mechanism shown in Fig. 4;

Fig. 6 is a broken elevation of a quench tank reciprocating mechanism.

Referring to Figs. 1, 2, and 3 of the drawings, the mechanism thereinshown is provided with a suitable supporting frame indicated generallyby the numeral ill and comprising upright members or posts II and spacedhorizontal members l2 and I3. The frame supports a motor M which by abelt 15 operates a pulley It for operating a rotary structure indicatedgenerally by the numeral H. The structure I! comprises a vertical ductl8 from which extend branch ducts l9v (two being shown) which conductgaseous fuel (preferably a mixture of domestic heating gas and ass-neeair) to an annular manifold 20. m the memfold the gas flows throughflexible ducts 2| each leading to a burner 22 which are supported byadonly are shown in the drawings for the sake of I simplicity, .but itwill be understood the required number of the same is employed forsupplying sufilcient heat to the stationary gear G for reds-j ing thetemperature thereof rapidly to the degree required for proper hardening.The details oi the burner structure, including the adjusting meanstherefor, are shown in detail in my copending application Serial No.460,499, filed October 2, 1942, now abandoned.

The rotary structure it is supported by suitable bearings 28 and 26mounted on the frame i6. A slip or swivel joint member 21 of known form.and comprising a lower rotary portion 27a and an upper non-rotatableportion 21b enables the structure ii to rotate with reference to anupper non-rotary extension thereof comprising a duct 28 into which thegaseous fuel is conducted by a pipe 28 from a fuel source not shown.Within the ducts i8 and 28 is a rotary axial sleeve 86 having at theupper end 3i a gas-tight packed Joint and at the lower end is secured'as by welding to a nut 92 which is threadedly received within the lowerend of the member 33 which carries the gas distributing arms 09. Gaseousfuel entering the duct 28 through pipe. 29 flows downwardly through theannular gas passage as to the branchducts i9, to the manifold and thenceto the burners as described.

Through the sleeve 30 extends a recipri-icable rod which at its upperend is attached to 8. Diston 36 operable within a vertically disposedcylinder 37 mounted on the upper end of the duct 28. 'Blue lower end ofthe rod 85 is provided with a gear engaging member 38 provided withmembars which operate automatically for engaging a:

gear to be elevated when the member 38 is passed downwardly through theaxial opening of a gear.

The automatic gear engaging members. in the form of the inventionillustrated; comprise unbalanced fingers 39 (see Figs. 4 and 5) whichare positioned in a diametrical slot 60 in the member 38 and pivotallymounted at 6| at the lower ends.

The members have a tendency to fall or tilt at their upper endsoutwardly of the slot and so present surfaces 52 in a horizontalposition for engagement with a gear or a gear supporting memher when thelower end of the member 38 has been passed through the axial opening ofa gear.

For convenience in initially locating a gear to be heat treated in axialalignment with the recipj rocating pick-up member 38, a hand operablegear locating member is provided which as shown is 'in the form of alever 43 pivotally mounted at I to the frame It! and having a pair ofarms 45 the outer ends of which slide on and are supported by i an,arcuate track 58. The member 53 can be 3 swung counterclockwise fromthe position shown 5 in Fig. 3 through an arc of approximately 90 or 3to the dotted line position indicated in said fi ure wherein a gear tobe hardened can conveniently be placed thereon by an attendant withoutreaching under the burners 22. Such a-gear is placed 4 in the spacedefined by three adjustable stops 41 which are so positioned that whenthe lever with the gear thereon is swung to thefull line position ofFig. 3, the axial opening in the gear will be in vertical alignment withthe pick-up member til. A suitable stop, such as shown at 48, arreststhe clock-wise movement of the lever in the position wherein the axialopening of the gear is in proper alignment for receiving the gearpick-up member SI upon descent of the rod 35.

For the purpose of operating the rod 35 fluid under pressure. such asair or a liquid, is admitted to the cylinder 31 from a pipe 49 undercontrol 01' a valve 50 of suitable construction and provided with amanually operable handle 5| as shown in Fig. 3. A pipe 52 is shownextending to the valve from a pressure tank 58 which constitutes asource of supply of operating fluid. By operating the valve handle inone direction the piston 36 is moved downwardly while reverse movementof the valve admits pressure fluid through a pipe 54 which leads fromthe valve to the lower portion of the cylinder 31 for forcing. thepiston upwardly. The construction of the valve is such asto bleed thefluid from pipe 52 or 54 through outlet cock 55 when the other pipe isreceiving pressure fluid fromthe tank. When the valve handle BI is in acentral or vertical position, the pressure fluid is not admitted toeither pressure line. The construction of the valve is wellknown and isnot illustrated in "detail in the sired to. elevate a gear into theheating position centrally of the annularly arranged burners, such agear is first placed on the gear centering lever 43 when the latter isin the dotted line position and the lever then swung to the full lineposition shown in Fig. 3. Thegear in position G of Fig. 3 correspondsto-the position G of Fig. 2. By operating the valve handle 5| in theproper direction the piston is moved downwardly to cause the pick-upmember 88 to pass through the central gear opening, the fingers or dogs39 thereupon swinging inwardly into the slot 38 by contact with the wallof the gear passage. When the dogs have passed through the gear theyfall outwardly. to the position shown in Fig. 4, whereupon reversal ofposition of the valve handle 5| efiects upward movement of the piston36, red 35 and member 88, for raising the gear G of Fig. 2 into theheating position G indicated in said figure.

As illustrated in Figs. 4, the gear G, instead of resting directly uponthe gear locating lever 43 is supported by a member 56 which is providedwith an annular flange 56a and a tubular extension 56b which has anexterior diameter for reception within the axial passage of the gear andan internal diameter for receiving the pick-up member 38. Suchsupporting member 56 thus is picked up by the member 38 and is movedwith the gear into heating position. The use of members 56 avoids thepossibility of a gear becoming tilted or improperly engaged as mightoccur should one of the dogs 39 register with a keyway in a gear. By useof washers of proper size dropped down of tubular portions 56a of themember 66, the latter can be employed with gears the central openingsofwhich are of greater diprovided with an adjustable stud 51 extendinginto the cylinder for arresting upward movement of the piston wherebythe stationary position of the gear within the heating zone can bealtered as may be found desirable. During the heating of the gear to thehardening temperature in the embodiment of the invention disclosed inthe drawings, the gear remains stationary while the burners rotate withthe rotatable structure ll thus directing flames upon the gear to raisethe latter or selected portions thereof. such as the toothed peripheryto the required temperature.

For procuring uniform hardening of the teeth of the gear or the surfaceof other articles, and

for avoiding distortion due to warping, it is necessary that the partsor portions to be hardened be subjected uniformlyto the heating effectsof the flames. Thus, if a gear is positioned even slightly off-centerwith respect to the paths of the rotating burners or if the gear shouldmove-slightly radially from a true central position relative to theburners, there is likely to be some lack of uniformity in thetemperature of the surface or surfaces, such as of the teeth of thegear, and hence variations in flnal hardness as well as distortion afterquenching. By reason of the fact that the gear is supported in heatingposition by the shaft 35 which is co-axially arranged with respect tothe rotary burners, relative lateral movement of the burners withreference to the gear or of the latter with respect to the former isavoided and hence the flame of each burner will produce a unifom heatingeffect in an annular band or path upon the gear. The burners areadjustable as stated and when adjusted, after test, to provide theproper application of heat, require no further adjustment generally inheating other similar gears which are to be similarly hardened. Byavoidin variations in the application of heat to the gear' by eachburner as it rotates about the gear by reason of the maintainedconcentricity 6 ward movement of the tank in the desired position.

The means shown for effecting the horizontal reciprocation of the tank58 comprises a piston rod 8| (see Fig. 6)-the forward end of which isattached to the forward portion of the tank by a bracket 82. A piston 53at the rear end of the rod 6| operates in a horizontal cylinder 64,positioned generally between the tracks 60 and beneath the tank.

A valve 55, similar to valve 50, is provided for controllong the flow ofpressure fluid into the ends of the cylinder 64 for effecting theoperation of the piston in the selected direction. As shown in Fig. 3, apressure fluid pipe 66 extends from the valve 65 t9 the forward end ofthe cylinder 64 while a similar pipe 61 extends to the rear end of thecylinder. By operating the handle 68 of the valve the. flow of pressurefluid to either side of the piston can be controlled for operating thelatter and hence operating the tank 58 from one to the other of the fullline or the dotted line position shown in Fig. 3.

In the dotted line position the tank is axially centered with respect tothe gear pick-up member 38 and hence when the latter is lowered the gearcan be deposited directly within the quench tank.

For the purpose of effecting release of the dogs 38 from the gear, orthe gear support 56, when the gear is lowered into the tank, the latteris provided with a gear receiving member 68 shown mounted on the bottomof the tank in the center thereof. The member 69 (see Fig. 5) has a base69a secured to the bottom of the tank, an upright tubular portion 691:having a central passage 690 of a diameter to receive the pick-up member38, and a horizontal annular flange 69d upon which the gear support 56is adapted to rest. When the of the paths of the burners with respect tothe in tank is in the gear ec i in position s own by gear, a highuniformity of hardness can be obtained in treating a batch of likegears. The rotation of the burners with reference to the article to behardened rather than of the article with reference to the burners is ofparticular advantage with respect to settin up the burners for heatingan initial gear of a batch of gears in that proper adjustment of theindividual burners can be made when necessary as the burners rotatewithout the attendant having to move about the machine as wouldbenecessary were the burner stationary. Adjustments of burners, whennecessary can be made quickly during operation, as will be seen, andhigh uniformity of heating, with uniformity in hardness effected anddistortion and warpage substantially or wholly avoided.

After a gear has been heated to the proper temperature, it is loweredpromptly into a quenching medium which may be a body of oil or water orinto a spray of either. For cooperation with the vertically reciprocablegear pick-up mechanism described above, a horizontally reciprocablequench tank 58 is provided which, in the embodiment of the inventionshown in the drawing, is provided with rollers 59 which travel onhorizontal channel shaped track members 68 supported by the frame of themachine. The tank 58 is arranged to be moved forwardly or to the leftfrom the position shown in full lines in Fig. 1 to the dotted lineposition whereby when a gear in the elevated position of Fig. 2 has beenheated to the proper temperature, it may be lowered immediately into thequench tank by the above described operation of the valve handle 5|. Thetracks 88 are provided with stops 60a for arresting the fordotted linesin Fig. 3, the dog release member 69 will be in axial registration withthe member 38 and upon the lowering of the heated gear into the tank 58,the lower end of the member 38, including the dogs 39 will enter thealigned passage 690. The dogs will be pressed inwardly of the slot 40 bythe wall of the passage 680 as the rod 35 completes its downward stroke.The inward movement of the dogs elevates the gear and member 56slightly, but as the dogs enter the slot 40, the gear and member 56 aredeposited upon the flange 69d. Reversal of the position of the valvehandle 5i will elevate the rod and member 38, as described above,leaving the gear G and support 56 at rest upon the horizontal flange56a. The upper ends of the dogs are shaped to avoid re-engagement withmember 56 as they are moved upwardly from the position shown in Fig. 3.

Quenching fluid is admitted to the quench tank 58 as required, dependingon the character of quenching best calculated to produce the degree ofhardness desired. For example, the tank may head 10 which is shownpositioned substantially 4 in the horizontal plane of the gear G in Fig.2 and is provided with a plurality of radially directed spray ports forspraying fluid upon the hot gear. Fluid is supplied to the spray ring 10by a flexible hose H (see Fig. 2) which is connected to one outlet of atwo-way valve I2 whereby fluid flowing from a motor operated pump IIthrough pipe 14 can be directed into the ring or into a tank 15 fromwhich fluid flows through pipe 78 to the inlet of the pump. Where a gearbeing heated is to be spray quenched, the spray may be in operationasthe tank 58 is moved forwardly in the gear receiving position beneaththe burners, an outlet duct 11 near the bottom of the tank andcontrolled by a valve 18, conducting the fluid from the spray tankthrough discharge pipe it into the main reservoir or tank '35. Thedischarge pipe 19 is attached to the spray tank fifi and reciprocatestherewith, the main fluid tank '55 being sufliciently long to receivethe fluid from the pipe 79 when the latter is in either extreme positionof reciprocation.

When a hot gear is lowered into the tank .58 by the operation of the rodand deposited upon the member 69, it may be subjected immediately to thesprayed fluid. The gear may be cooled to flnal temperature by the sprayif desired, but a common practice is to employ spray quenching initiallyonly and hence where the gear after initial spray quenching is to beimmersed in the fluid, the valve 78 is closed at the proper time wherebythe fluid from thespray ring 70 accumulated within the tank 58 andsubmerges the gear. The fluid may rise in the tank 58 until it overflowsthrough an overflow pipe 80 which communicates with the discharge pipe59 and through which the overflowing fluid is returned to the main tank15. When the gear has been sufiiciently cooled, the operation of thepump may be interrupted or preferably especially where a batch of gearsis being treated, the valve 72 is operated to direct the fluid from thehose ll through a discharge pipe BI which directs it into the main tank.The drain cock 78, when opened permits the fluid in the quench tank 58to drain into the main tank '85. The fluid in the latter may be cooled,if desired, by circulation through a cooling unit, not shown.

It will be understood that by means of the reciprocating quench tank 58and the fluid control means shown, a hot gear upon being deposited inthe quench tank is subjected immediately to the action of the fluideither by a spray thereof or by submergence in an accumulated body offluid in the tank and that upon elevation of the gear pick-up member 38from the tank, the latter can be moved rearwardly to the full lineposition of Fig. 1 whereby another gear, previously positioned on thelocating lever 63,can be swung by operation of the latter into alignedposition for elevation by the pick-up member into heating relation.While the latter gear is being heated, the gear in the quench tank whensufflciently cooled can be removed, the fluid therein discharged, ifdesired, and the tank made ready for the quench of the next gear.

This arrangement not only provides for immediate quenching of the gearsor articles when a proper temperature has been reached, but either sprayor immersion quenching may be employed and with expeditious handling ofthe gears especially where a numberof the like articles are to behardened.

By providing a second reservoir similar to tank 15 for a second typequenching fluid, and providing proper connections between such secondtank, pump I3 or a second such pump and the quench tank 58, a selectionof quench fluid can be made available. Thus one tank 15 may containwater and the other oil, so that either fluid may be employed in thequch tank 58 as mayv be desired.

, ers located coaxially of the axis of rotation of the burners,- and areciprocable member extending from said duct provided with articlesupporting means for supporting an article coaxially with respect tosaid burners.

2. Flame hardening apparatus comprising a rotary structure, burnerscarried thereby for directing flames inwardly of the paths of movementthereof upon an article positioned coaxially with respect to the axis ofrotation of said burners, a duct for supplying fuel to said burners andlocated coaxially with respect to said paths, and a non-rotaryreciprocable member extending coaxially from said duct and provided withmeans for engaging an article therebeneath and elevating the same into aheating position coaxial with respect to said burners.

3. Flame hardening apparatus comprising a rotary structure providd witha plurality of rotary burners directed inwardly of the paths of rotationthereof, means for supplying fuel to the burners comprising a rotaryduct positioned coaxially with respect to the burners, a reciprocablearticle carrier member extending coaxially from said duct and'providedwith article engaging means for engaging a subjacent article andelevating the same into a heating position coaxial with respect to theburners and within the heating range thereof, and means for effectingthe reciprocation of said carrier member for moving an article to beheated to and from said heating position.

4. Flame hardening apparatus comprising a rotary structure provided witha plurality of burners arranged to direct flames inwardlly of the pathsof rotation thereof upon a coaxially positioned gear to be heated, areciprocal gear carrier operable coaxially within and through saidstructure, means above said structure for operating the carrier, meansat the lower end of the carrier arranged for entrance into the axialpassage of a subjacent axially aligned gear and comprising means forengaging. the gear whereby upon elevation of the carrier by saidoperating means the gear is elevated into a position within the heatingzone of the burners, a reciprocable quench tank operable to and from aposition beneath said gear carrier and means within the tank foreflecting the operation of said gear engaging means for releasing a.gear lowered into the tankby said carrier.

5. Flame hardening apparatus comprising a V rotary heating means fordirecting flames inwardly upon a coaxially positioned member to behardened, a reciprocable member movable coaxially of said rotary meansand provided with article engaging means for engaging a subjacentarticle located in alignment with said member for engaging and elevatingthe article into a position coaxial with respect to the rotary movementof the flames of said heating means, means for operating saidreciprocable member, a. quench tank movable into a position beneath saidheat- 9 ing means, and an article receiver in the tank for effecting therelease from said engaging means of an article lowered upon the same bysaid reciprocable member.

6. In an apparatus for hardening articles by heating and quenching,means for applying heat to an article, carrier means for moving thearticle vertically to and from the heatapplying means, means forreciprocating the carrier means, a quench tank horizontally operable toand from a position in vertical alignment with the carrier, means forcontrolling the operation of the carrier and said tank for effecting thedelivery by the former of a heated article into the latter when saidmembers are in alignment, and means positioned within the tankcooperable with the carrier upon descent thereof into the tank foreffecting release from the carrier of the article when the latter is ina given position within thetank.

7. Article hardening apparatus comprising a source of heat, a verticallyreciprocable article carrier provided with article engaging means forengaging and elevating an article into and lowering the same from aheating zone of said source, a reciprocable quench tank, means foroperating the same to and from article receiving posiof the article intoreceiving position within the tank.

, 8. Hardening apparatus for gears provided with central passagescomprising a source of heat, a vertically reciprocable member providedwith a gear pick-up member movable through the pas- 1 40 retracted bycontact with the wall of the gear passage upon entrance of said memberinto said passage and to move to the extended positions upon movement ofsaid fingers through the passage for engaging and supporting the gearupon reverse movement of said member, means for reciprocating saidpick-up member for engaging a gear and moving the same into heatingrelation with respect to said heat source, a quench tank and means inthe tank comprising a gear support adapted for alignment with saidpick-up member and provided with a recess into which the pick-up memberis movable for effecting retraction of said fingers for releasing thegear for de positing the same within the tank.

ERNST A. FURKERT.

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